Franz l



1mm s@ (No Model.)

P. L. 8U H. MRMANN PERCUSSION FUSE FOR BLASTVING. y

Pafented Nov. 5, 1889.

l. ab v afs WWA/55553:

vUNIITIED STATES" PATENT Orrlcnf FRANZ I.. TmnANN AND I'IANSTIRMANN, orvIENNA, AUSTRIA-IIUNGARY, AssIeNoIts, l Dv DIRECT AND IneensASSIGNMENTS, To TIIE UNITED sTATEs MINE sUPrLms COMPANY.

PERCUSSION-Euseroa BLAsTlNe.

SPECIFICATION forming part of Letters Patent No. 414,662, dated November1889. j 'I 'Application filed December 13, 1887. Serial No. 257,784. (Nomodel.)

To all whom i., may concern:

Be it known that we, FRANZ L. TIRMANN, mining engineer, and HANSTIRMANN, Inechanician, citizens of Austria, and residents of 5 Vienna,in the Empire of AustIia-I'lungary,

have invented certain new and useful Improvements in Blasting-Fuses, ofwhich the following is a specification. V This invention relates tofuses for blasting ro and analogous purposes, (such as the firing ofcannon,) of the class known as percussion fuses, or those wherein theprimer or eXplosive is exploded by being struck by a hammer. Fuses ofthis class have been made with a spring tending to throw the hammerforward, and with a det-ent to release the hamnier, the detent beingwithdrawn by pulling n a wire or lanyard. Such fuses are dangerous "I tohandle and use because of the liability that 2o the hammer may be.released prematurely.

' According to another construction the hammer is normally pressedagainst the primer by the spring, and a'pull wire or cord is connectedto the hammer, which, when pulled, draws it back and compresses thespring, and on the pull being increased the wire or cord breaks ordisconnects itself from the hammer, so that the latter is released andis permitted to Hy forward under the impulse of 3o the spring andexplode the primer. This construction is liable to premature explosionby the accidental pulling and release of the wire.

Our present invention provides a percussion-fuse which can be safelytransported, handled, and used. The hammer is normally partly retracted,being so held against the tension of its spring by a safety-stop, whichprevents its moving forward far'enough to .reach the primer. lVhen thepull-wire is 4o pulled, the hammer is drawn fully back, the spring fullycompressed, and on increasing the pull the wire is disconnected, so thatthe hannner is released and iiies fully forward against the primer. Thusthis extraordinary pull is necessary to release the hammer and cause itto strike the primer.

Figure l of the accompanying drawings is a longitudinal mid-section ofour improved fuse constructed for blasting purposes. Fig.

2 is a side elevation thereof. Fig. 3 is a sec- 5o tional viewillustra-ting a modified construction. L and 5 show other modifications."XVe will first describe the construction shown in Figs. l and 2,wherein a designates the head of the fuse, which may be made of wood ormetal, and b designates a tube forming the body of the fuse,and whichmay be made of wood, metal, or paper. Vithin the tube ZJ are placed aspiral spring c and a hammeror plunger d. The rear end of this ham- 6omeris formed with an eye, with which engages the hooked end of a wire g.This wire extends out through a hole formed in the center of the head a,is made of any suitable length, and is preferably bent into a loop oreye at its otherend. Acap e, containing detonating maferial-such asfulminate, dynamite, or other explosive compound suitable for effectingthe firing of the blasting-eharge-is' Iixed in the front end of the tubeb by means of suitable 7o cement or otherwise. The displacement of thiscap toward the hammer d is prevented by means of a bead j, formed in thetube l), and projecting internally, so as to constitute a flange orshoulder against which the cap 75 may rest. The cap c consists of ametallic cup partly filled with the dctonating mate-Y rial, and into theopen end of which is placed a small metal disk perforated at its center.Against this plate is gummed or cemented a 8o primer f, which may be acommon paper cap, such as is used with toy pistols.

In puttin g together our percussion-fuse we Iirst pass the wire rythrough the hole in the head a, then slip the spiral spring c over it,then bend the end of the wire into a hook and engage it with the eye onthe hammer d, 'and then pull back the wire until the hammer is drawnback to about the position presses the spring to some extent. We thenform a loop 7L in the wire g, which loop comes against .the surface ofthe head a and forms a safety-stop, which prevents the wire being drawnforward by the tension ot' the spring c. 95 The tube l1 is then slippedover the hammerand spring and its end is fastened into the recess in thehead a by means of putty or shown in Fig. l, whereby the hammer com- 9o102` AMMUNITION AND EXPLOSIVE DEVICES 'other suitable cement@ The "cape. isV then inserted into -the opposite end of the tube and fastenedtherein by putty or other cement, the primer f having been previouslyaffixed to the cap. The loop h in the wire g prevents the accidentalthrowing forward of the hammer against the cap, whereby accidental orpremature explosion of the primer is avoided.

Our percussion-fuse is operated as follows: The head a being suitablyfixed in place, the wire g is pulled, either by taking hold of itdirectly, if it be long enough, or by pulling a cord attached to itslooped end. -The first eifect of this pull is to draw back the hammer duntil the spring c becomes fully compressed, whereupon the force of thepullis increased sufficiently to open out the hook on the end of thewire until it disengages itself cushioned by a mass of confined air.

from the ear of the hammer, whereupon the latter is set free and isinstantly and violently thrown forward against the primer f, therebyexploding the cap, which in turnv tires the charge in the mine.. Theresistance of the wire should be such that the pull necessary to effectthe explosion ofthe percussionfuse shall amount to about ten or elevenkilograms.

The transportation and handling of our percussion-fuse is unattendedwith danger, since the power necessary to pullout the wire is soconsiderable thatno manipulation to which the fuse is ever subjected caneffect a `pull sufficient to prematurely discharge the fuse. By using awire of larger diameter this factor of safety can be increased to anydesired extent.

The use of our fuse requires no special accessories, such as pulleys,rings, and the like, which are necessary in the use of frictional fuses,and the connecting of wires, which is essential with electric fuses, isavoided.

Our percussion-fuses can be made at a less cost than frictional fuses.

In the modification shown in Fig. 3 the head CL is made of metal and hasits eentral part projecting so that it tits into the tube b. The primerf in this construction is alixed to the front end of the hammer (Z,which produces the same effect as if it were affixed to thecap c. Thecap is fastened in place in the tube b by bending down ears ii, formedonthe end of the tube. The hammer d is not made a close fit with the tubel), but is sufficiently smaller than the tube to permit the air to passfreely around it. during its forward motion, so that the force of itsblow is not materially reduced by its being This end may be accomplishedby making the hammer of polygonal cross-section,or by forming holeslongitudinally through it, as shown in dotted lines in Fig. 3. Thehammer may be of greater or less weight, according to the force of theblow necessary t-o explode the primer and according t-o the strength ofthe spring. It lnay even be made practicable to dispensxeentirely withany distincthammer,

i i l j 414,662

properly so called, provided that some equivalent part be substitutedwhich shall perform the same function. Thus any part or element which,upon the expansion of the spring,

shall strike the primer with suiiicient force will serve the purpose.For example, the end of the spring may be made to strike the primer,thus combining in one part the functions of both the spring and thehammer.

Fig. 4 illustrates a modified construction wherein the tube orinclosing-case is formed of a block of wood, suitably bored out, withthe cap e fixed in its front end.Y The hammerd is made of soft met-aland cast upon the end of a wire or pin g, which passes out through ahole in the head of the case, and its outer end is bent into an eye 71.,which under the tension of the spring c is drawn against theend of thecase and prevents the pressing forward of the hammer against the'primer. To this eye his attached the wire or cord d', by pulling whichthe fuse is exploded. This viewis introduced to illustrate amodification of the destructible or separable connection between thehammer and the wire g, which in the previous figures consists of thehooked end of the wire. In this construction this destructibleconnection consists of the casting of theipiain end of the wire into thehammer in such manner that upon a suficient pull being exerted-sa forIOC IIO

,Fig 5 shows a construction wherein the end of the spring seyes as thehammer. The

sprin g chere shown is a leaf-spring instead of a spiral spring, and isarranged radially in the head d, which is hollow, forming an in-Vclosing-case for the spring. The outer end of the spring is fastenedsecurely in this case, and its inner end is arranged at the center ofthe tube b, where it can strike the primer f of the cap e. The free endof the spring (1cttered d) lserves the purpose of the hammer,

and is bent into'an eye, with which engages the hooked end of the wireg. rlhis wire passes out through ahole in the center of the head and hasformed upon it an enlargement 7l, which may be Aa bent eye, as shown, ora drop of solder, or a winding of thread cemented to it by varnish, andwhich serves, as the safety-stop 71to prevent the forward'in ovement ofthe hammer into contact with the primer.

Fig. 3 shows the safety-stop h, formed by means of an enlargement on thewire g, as

-or explosive.

Aclearly shown, which maybe made a drop of solde-r or otherwise. l r

Any suitable mechanical equivalent of a spring may be substituted for itas a means for throwing the hammer against lthe primer We claim as ourinvention the improvements in fuses, substantially as hereinbefore setforth, and defined as follows, namely:

l. In a percussion-fuse, the combination of a spring-pressed hammertending to fly forward and normally partly retracted, with a safety-stopto hold the hammer so retracted and prevent its flying fully forward toex plode the primer, land a pull-wire connected to the hammer anconstructed to be discon nected by a sut-tici nt pull and thereby torelease the hammer and explode the primer.

2. A fuse Cons' ting of the combination, with an inclosing-case, of aspring-pressed hammer within said oase, tending to fly forward, andnormally partly retracted, a pullwire connected to said hammer, asafetystop on said wire arranged to be drawn by the spring-tension intoabutment against the ease and thereby to hold the hammer partlyvretracted and prevent its movement toward the primer, fand a separableconnection between said-'wire and hammer, whereby on the thereinarranged to be drawn by the spring-- tension into abutment against thecase and thereby to prevent the forward movement of the hammer beyondsaid partly-retracted positio'n, and said -wire constructed to disengagelthe hammer by a sufficient pull, whereby on the pulling of the wiretheY hammer is first drawn fully back, and upon increasing the pull theconnection between the wire and hammer is severed and the hammerreleased and permitted to ily against the primer.

SAO.

Signed at Vienna, in the Empire of Aus'` y FRZ. L. TIRMANN.

HANS TlRMANN.

tria,this 21st day of October, 1887.'

lVitnesses:

EDMUND JUSSEN, OTTO SCHEFFER.

